System-level throughput analysis for process variation aware multiple voltage-frequency island designs

The increasing variability in manufacturing process parameters is expected to lead to significant performance degradation in deep submicron technologies. Multiple Voltage-Frequency Island (VFI) design styles with fine-grained, process-variation aware clocking have recently been shown to possess increased immunity to manufacturing process variations. In this article, we propose a theoretical framework that allows designers to quantify the performance improvement that is to be expected if they were to migrate from a fully synchronous design to the proposed multiple VFI design style. Specifically, we provide techniques to efficiently and accurately estimate the probability distribution of the execution rate (or throughput) of both single and multiple VFI systems under the influence of manufacturing process variations. Finally, using an MPEG-2 encoder benchmark, we demonstrate how the proposed analysis framework can be used by designers to make architectural decisions such as the granularity of VFI domain partitioning based on the throughput constraints their systems are required to satisfy.